A beef wellington pie was the lunchtime dish that is believed to have left three people dead and one fighting for his life from a suspected mushroom poisoning, according to a source familiar with the situation.
Erin Patterson, 45, prepared the meal at her home in Leongatha on 29 July for her former parents-in-law Don and Gail Patterson, and Gail’s sister Heather Wilkinson and her husband, Ian.
The Pattersons, both 70, have since died, as has Heather, 66. Heather’s husband, 68-year-old Baptist church pastor Ian Wilkinson, remains in a critical condition in hospital.
Police said their symptoms were consistent with having eaten death cap mushrooms.
Police said Erin Patterson remained a suspect in the investigation because she had cooked the meal at her home but did not become ill.
However, they warned people not to speculate about the case, because it could turn out to be “very innocent”.
The death cap, Amanita phalloides, is the world’s most toxic mushroom and is responsible for about 90% of mushroom-related deaths globally. Its main toxin is α-Amanitin, which cannot be destroyed by cooking or drying, and can result in liver and kidney failure.
In its early growth stages, death caps have a white creamy colour that can resemble edible straw mushrooms. They typically grow under oak trees and are found in Victoria and the Australian Capital Territory, but rarely in other states.
Police are conducting forensic tests on items seized at the house, and also visited a nearby tip.
The incident has left the rural Victorian town of Korumburra, where Ian Wilkinson is a pastor, in mourning. Mushroom foraging is popular in the area, according to the local mayor.
Guardian Australia understands that the lunch behind the suspected poisoning included a beef wellington pie as its main course.
Common recipes for beef wellington pie call for the addition of mushrooms, with some suggesting chestnut or wild varieties.
In 2012, two people died in Canberra after eating death cap mushrooms at a New Year’s Eve dinner party.
